Hi guys, Can someone help me understand what’s go...

# coroutines

[Mauricio Barbosa]

Hi guys,

Can someone help me understand what’s going on with this code?

I’m trying to create a flow that merge the responses of some requests and emit a new value every time a response is retrieved.

For some reason this code crashes after the first request, printing the following log:

Doing first request
retrieving first request
Exception in thread "main" kotlinx.coroutines.JobCancellationException: Parent job is Completed; job=ScopeCoroutine{Completed}@383534aa

Has someone any ideia of what am I doing wrong?

Untitled

[Adam Powell]

Switch coroutineScope and flow in your nesting at the beginning of composedRequest(). You want the flow to have a scope, you don't want to have a scope for constructing the flow.

[Adam Powell]

The exception is because the coroutineScope is completed by the time composedRequest returns the new flow object, so when you collect it you're trying to use async to launch child coroutines of a parent that isn't active anymore

[Mauricio Barbosa]

Hi Adam,

Thanks for replying.

I think I understand what’s going on. But I still need a scope in order to use the async inside flow. So, what’s the correct approach? Can I encapsulate async inside a coroutineScope ?

[Adam Powell]

You should swap the positions of the coroutineScope and the call to flow {}

[Adam Powell]

And you can drop suspend from composedRequest

[Mauricio Barbosa]

It works! Thanks @Adam Powell